JP2683294B2 - Developer recovery device of developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer recovery device for recovering the expired developer in a developing device in an electrophotographic copying machine, printer or the like.

<Prior Art> Conventionally, in an electrophotographic image forming apparatus, a developer used for development has a lifespan when a phenomenon occurs in the order of several thousand to several hundred thousand sheets, and the image quality is deteriorated or the developer is It scatters and contaminates the inside of the main unit.

Therefore, it is necessary to replace the expired developer.
Therefore, the following technology has been disclosed as a developer recovery device for recovering a developer whose life has expired.

As a conventional example 1 of a developer collecting device, Japanese Patent Laid-Open No. 54-111354
The publication discloses a technique in which a collecting container is arranged in the circulation path of the developing tank and the developer remaining on the bottom of the developing tank is collected by a magnet. Also, Japanese Utility Model Publication No. 57-55623 discloses a method of moving a magnet to recover a developer.

As a conventional example 2, Japanese Patent Laid-Open No. 60-239775 discloses that a concave catch van is provided below the developing tank, and the developer is received by the catch van and collected in a collecting container.

As conventional example 3, JP-A-60-1007057 discloses a method in which a shutter at the bottom of the developing tank is opened over the entire length of the developer circulating portion and the developer is collected in a removable collecting container at the bottom of the developing tank. Is.

<Problems to be Solved by the Invention> In Conventional Example 1 described above, the developer remaining on the bottom of the developing tank cannot be completely recovered. In addition, the recovery work of the developer must be performed by a service person, which is troublesome and costly.

In Conventional Example 2, since the developer is once received by the cache, the developer may be scattered and the inside of the apparatus main body may be soiled.

In Conventional Example 3, since the shutter has to be manually opened and closed in the horizontal direction when the developer is collected, the work may be complicated, or the developer attached to the shutter may spill and stain the surrounding area.

In view of the above, an object of the present invention is to provide a developing and collecting device for a developing device, which allows a user to easily collect a developer whose life has expired, without any trouble and without getting dirty.

<Means for Solving the Problems> The means for solving the problems according to claim 1 of the present invention is shown in FIGS.
As shown in the figure, the developing roller 2 and the agitating roller 3 are rotatably installed in the developing tank 1, and the developer collecting container 4 is attached to one end of the developing tank 1, and the developer collecting container 4 is provided between the developing tank 1 and the collecting container 4. A developer discharging port 5 is formed, and is arranged below the developing tank 1 to convey the developer to the collecting container 4, and a covering means 30 for exposing and exposing the conveying means 6 in the developing tank 1.
And a controller 31 for controlling the driving of the developing roller 2, the stirring roller 3, the conveying means 6 and the covering means 30. The controller 31 controls the developing roller 2, the stirring roller 3 when the developer is replaced. Further, it is provided with a developer carrying function of driving the carrying means 6 and operating the covering means 30 so that the carrying means 6 is exposed.

<Operation> In the problem solving means according to claim 1, at the time of image formation, the controller 31 drives the developing roller 2 and the agitating roller 3 to perform the development while agitating the developer in the developing tank 1. At this time, the conveying means 6 is stopped, the upper half is covered by the covering means 30, and the developer is blocked.

Next, when the life of the developer is reached and it is time to replace it,
The control means 31 operates the covering means 30 to move the conveying means 6
Cover the bottom half.

Then, the developing roller 2, the agitating roller 3 and the conveying means 6 are driven, the developer in the developing tank 1 is accumulated under the developing tank 1 by the developing roller 2 and the agitating roller 3, and is conveyed by the conveying means 6 in the discharge port 5 direction. Be transported to. Then, the developer is collected in the collection container 4 through the discharge port 5.

Therefore, the developer collecting operation can be automatically performed, and the user can easily perform the operation without getting dirty.

Further, at the time of image formation, the bottom portion of the developing tank 1 is covered with the covering means 30.
The amount of the developer used can be reduced and the amount of the developer accumulated at the bottom of the developing tank 1 can be reduced, so that the utilization efficiency of the developer can be improved.

<Examples> Hereinafter, respective examples for each claim of the present invention will be described with reference to the drawings.

(First embodiment)

FIG. 1 is a side view of the developer collecting device of the developing device showing the first embodiment, FIG. 2 is a sectional view of the developing device, and FIG. 3 is a control block diagram of the same.

In the developing device of the present embodiment, a developing roller 2 and a stirring roller 3 are rotatably installed in a developing tank 1, a developer collecting container 4 is attached to one end of the developing tank 1, and the developing tank 1 and the collecting container 4 are provided. And a developer discharge port 5 is formed between

The developer collecting device is arranged below the developing tank 1 and carries the developer to the collecting container 4, a shutter 7 for opening and closing the discharge port 5, the developing roller 2, and a stirring roller 3. Also, a first controller 8 for controlling the driving of the conveying means 6 and the opening / closing of the shutter 7 is provided, and the first controller 8 controls the developing roller 2, the stirring roller 3 and the conveying means 6 during image formation. It has an image forming function of driving the shutter 7 to the closed posture, and a developer collecting function of driving the developing roller 2, the stirring roller 3 and the conveying means 6 at the time of exchanging the developer to put the shutter 7 in the open posture. It has been confused.

In the developing tank 1, as shown in FIG. 2, an opening 10 is formed along the axial direction on the side surface facing the photoconductor, the developing roller 2 is arranged on the opening 10 side, and the stirring roller 3 is arranged on the opposite side. Are arranged, and are driven to rotate in a direction indicated by an arrow in the figure.

A toner replenishing tank 11 is mounted above the stirring roller 3, and a toner replenishing roller 12 is rotatably provided at a communication port between the toner replenishing tank 11 and the developing tank 1.

Further, above the space between the developing roller 2 and the stirring roller 3,
A developer cartridge 13 is detachably attached and is sealed by a seal material 14. An electric shutter 16 is provided at the developer replenishing port 15 between the cartridge 13 and the developing tank 1 to open and close the developer replenishing port 15.

 In FIG. 2, 17 is a doctor.

The discharge port 5 is formed in the lower part of the end surface orthogonal to the axial direction of the developing tank 1. The collection container 4 is arranged so as to face the discharge port 5, and a discharge cylinder 18 is fitted through the upper side surface of the collection container 4.

The discharge cylinder 18 is closed at one end inside the collection container 4, has a drop port 19 formed on the lower surface, and the other end is connected to the discharge port 5 of the developing tank 1.

The carrying means 6 is composed of a carrying screen which is rotatably supported in the developing tank 1 in the same direction as the developing roller 2 and the agitating roller 3, and is formed in the bottom of the developing tank 1 and has a semicircular shape protruding downward. It is arranged in the groove 20. The outlet 5 is opened at one end of the groove 20.

The shutter 7 is arranged between the discharge port 5 of the developing tank 1 and the discharge cylinder 18 of the recovery container 4, and is vertically moved along the outer wall of the developing tank 1 by driving a motor or the like.

The first control device 8 is composed of a microcomputer, and operates the developer collecting function when the developer exchanging switch 21 is turned on or when the developer exchanging simulation mode is set. Further, after the developer is collected, the shutter 7 is moved downward to close the discharge port 5, and the electric shutter 16 of the developer cartridge 13 is opened to put the developer into the developing tank 1.

In the above structure, during normal image formation, the first controller 8 drives the developing roller 2, the stirring roller 3 and the conveying means 6 to stir the developer in the developing tank 1,
The developing roller 2 develops the photoconductor. At this time, since the shutter 7 closes the discharge port 5, the developer carried by the carrying means 6 is not discharged from the discharge port 5, and the developer accumulated at the bottom of the developing tank 1 is agitated.

Next, when the life of the developer is reached and it is time to replace it,
First, attach the developer cartridge 13 to the upper part of the developing tank 1,
Peel off the sealing material 14. At this time, the electric shutter 16 is closed.

Then, when the developer exchange switch 21 is turned on, the shutter 7 is moved upward by the first control device 8 to open the discharge port 5. Further, the developing roller 2, the stirring roller 3 and the conveying means 6 are driven, and the developer in the developing tank 1 is accumulated in the groove portion 20 below the developing tank 1 by the developing roller 2 and the stirring roller 3 and discharged by the conveying means 6. It is conveyed in the direction of the exit 5. Then, the developer is sent from the discharge port 5 to the discharge cylinder 18, and is dropped from the drop port 19 into the collection container 4 to be collected.

When the developing roller 2, the agitating roller 3, and the conveying means 6 are driven for a certain period of time to finish the collection of the developer in the collection container 4, the shutter 7 moves downward and the discharge port 5 is closed.
Then, the electric shutter 16 of the developer replenishing port 15 is opened, and a new developer is introduced from the cartridge 13 into the developing tank 1.

Therefore, since a series of operations from the collection of the old developer to the introduction of the new developer are automatically performed, the user can easily perform the work conventionally performed by the service person without getting dirty. .

Moreover, since the conveying means 6 operates as an auxiliary stirring roller during image formation, the stirring property of the developer can be improved, and the developer that has accumulated at the bottom of the developing tank 1 and does not contribute to the development can be lost. It is possible to extend the life of the agent and stabilize the image quality.

(Second embodiment)

FIG. 4 is a side view of the developer collecting device of the developing device showing the second embodiment, FIG. 5 is a sectional view of the developing device, and FIG. 6 is a control block diagram of the same.

The developer collecting device of the present embodiment is arranged below the developing tank 1 to convey the developer to the collecting container 4, and a covering means for exposing the conveying means 6 in the developing tank 1 so as to be exposed and shieldable.
30 and a second control device 31 for controlling the drive of the developing roller 2, the stirring roller 3, the conveying means 6 and the covering means 30 are provided, and the second control device 31 uses the developing roller at the time of replacing the developer. 2, drive the stirring roller 3 and the conveying means 6,
Further, it is provided with a developer carrying function for operating the covering means 30 so that the carrying means 6 is exposed.

The configuration of the developing tank 1 and the transporting means 6 are the same as those in the first embodiment, and thus detailed description thereof will be omitted.

The covering means 30 is an elongated plate having a semicircular cross section which is rotatable around the screw of the conveying means 6.
By covering the upper half of the entire length of the developer, the developer and the conveying means 6 are shut off, and the conveying means 6 is exposed in the developing tank 1 by rotating 180 degrees to cover the lower half of the conveying means 6. It becomes a transportable state.

The second control device 31 is composed of a microcomputer, and has the developer transport function which is activated when the developer exchange switch 21 is turned on or when the developer exchange simulation mode is set, and image formation. Sometimes developing roller 2
And a function of driving the stirring roller 3 to operate the covering means 30 so that the conveying means 6 shields the developer from the developer. Further, similar to the first control placement 8 of the first embodiment,
It also has a function of opening and closing the electric shutter 16 of the developer cartridge 13.

In the above configuration, during normal image formation, the second control device 31 drives the developing roller 2 and the stirring roller 3 to perform the development while stirring the developer in the developing tank 1.
At this time, the transporting means 6 is stopped, the upper half portion is covered by the covering means 30, and is shielded from the developer.

Next, when the life of the developer is reached and it is time to replace it,
First, attach the developer cartridge 13 to the upper part of the developing tank 1,
Peel off the sealing material 14. At this time, the electric shutter 16 is closed.

Then, when the developer exchange switch 21 is turned on, the elongated plate of the covering means 30 is rotated by a half by the second control device 31 to cover the lower half portion of the conveying means 6.

Then, the developing roller 2, the stirring roller 3 and the conveying means 6 are driven, the developer in the developing tank 1 is accumulated in the groove portion 20 at the lower part of the developing tank 1 by the developing roller 2 and the stirring roller 3, and is discharged by the conveying means 6. It is conveyed in the direction of the exit 5. Then, the developer is sent from the discharge port 5 to the discharge cylinder 18, and is dropped from the drop port 19 into the collection container 4 to be collected.

When the developing roller 2, the stirring roller 3 and the conveying means 6 are driven for a certain period of time to complete the collection of the developer into the collecting container 4, the long plate of the covering means 30 is rotated again by half and the conveying means 6 is carried out.
The transfer means 6 is shielded from the inside of the developing tank 1 by covering the upper half part thereof. Then, the electric shutter 16 of the developer supply port 15 is opened, and a new developer is introduced into the developing tank 1 from the cartridge 13.

Therefore, also in this embodiment, similarly to the first embodiment, the developer collecting and charging operations can be automatically performed, and the user can easily carry out the operation without getting dirty.

Further, at the time of image formation, the bottom portion of the developing tank 1 is covered with the covering means 30.
The amount of the developer used can be reduced and the amount of the developer accumulated in the bottom of the developing tank 1 can be reduced, so that the utilization efficiency of the developer can be improved.

(Third embodiment)

FIG. 7 is a side view of the developing and collecting device of the developing device showing the third embodiment, FIG. 8 is a sectional view of the developing device, and FIG. 9 is a control block diagram of the same.

The developer collecting device of the present embodiment controls the driving of the conveying means 6 arranged below the developing tank 1 for conveying the developer to the collecting container 4, the developing roller 2, the stirring roller 3 and the conveying means 6. A third controller 40 is provided, and the third controller 40 has an image forming function of driving the developing roller 2 and the stirring roller 3 at the time of image formation, and the developing roller 2 and the stirring roller 3 at the time of replacement of the developer. And a developer discharging function for driving the conveying means 6.

The construction of the developing tank 1 and the conveying means 6 are the same as those in the first embodiment, and therefore detailed description thereof will be omitted.

The third control device 40, which is composed of a micro computer, activates the developer discharging function when the developer exchanging switch 21 is turned on or when the developer exchanging simulation mode is set, and after a certain period of time elapses. It also has a function of opening and closing the electric shutter 16 of the developer cartridge 13.

In the above structure, the third control device 40 is used during image formation.
The developing roller 2 and the agitating roller 3 are driven by the above, and at the time of replacement of the developer, the developing roller 2, the agitating roller 3 and the conveying means 6 are driven to collect the developer and a new developer as in the first embodiment. Input.

Therefore, also in this embodiment, the developer can be collected and put in automatically, and the user can easily carry out the work without stain.

[Fourth embodiment]

FIG. 10 is a side view of the developing and collecting device of the developing device showing the fourth embodiment, FIG. 11 is a sectional view of the developing device, and FIG. 12 is a control block diagram of the same.

In the developer collecting device of this embodiment, the developing tank 1 in which the developing roller 2 and the agitating roller 3 are rotatably installed is rotatable around the rotation shaft 50, and the developer discharging means arranged above the developing tank 1. 51 and a fourth controller 52 for controlling the driving of the developing roller 2, the stirring roller 3 and the discharging means 51 and the rotation of the developing tank 1 are provided, and the fourth controller 52 is provided at the time of replacing the developer. The developing tank 1 is rotated 180 degrees to drive the developing roller 2, the stirring roller 3 and the carry-out means 51 so as to have a developer discarding function.

In the developing tank 1, as shown in A in FIG. 11, an opening 10 is formed along the axial direction on the side surface facing the photoconductor, and a developing roller 2 and a stirring roller 3 are arranged in order from the opening 10 side. ,
It is rotationally driven in the direction of the arrow in the figure.

A toner replenishing tank 53 is detachably attached above the stirring roller 3, and a communication port is formed between the toner replenishing tank 53 and the developing tank 1, and the toner replenishing tank 53 is provided in the communication port.
A toner replenishing roller attached to is disposed. The rotating shaft 50 is attached to an end portion of the developing tank 1 opposite to the opening 10 side and is rotatably supported by the image forming apparatus main body.

The rotating shaft 50 is rotationally driven by a developing tank driving device 54 such as a motor, so that the developing tank 1 is in the A position at the time of image formation.
Switch from the posture to the posture B when rotating the developer 180 degrees.

The carrying-out means 51 is composed of a carrying screen, and is rotatably mounted on a semicircular holding portion 55 formed on the upper portion of the developing tank 1 and protruding outward. The discharge port 5 is opened at one end of the holding portion 55.

The collection container 5 is attached to the discharge port 5 in the B posture of the developing tank 1, and a detection switch 56 for detecting the presence or absence of the collection container 4 is provided near the discharge port 5. ing.

The fourth controller 52, which is composed of a microcomputer, activates the developer discarding function when the developer exchanging switch 21 is turned on or when the developer exchanging simulation mode is set. Further developer change switch
It has a function of returning the developing tank 1 from the B posture to the A posture by turning on 21. Further, in the B posture of the developing tank 1, when the collecting container 4 is not attached to the discharge port 5, a safety function is provided so that the carry-out means 51 is not driven by a signal from the detection switch 56.

In the above structure, when the image is formed, the developing roller 2 and the stirring roller 3 are driven to perform the development. At this time,
The developing tank 1 is in the posture A, and the carry-out means 51 is not driven.

Next, when the developer has reached the end of its life and needs to be replaced, when the developer replacement switch 21 is turned on, the rotation axis is rotated by the fourth controller 52.
When 50 is driven, the developing tank 1 rotates 180 degrees from the A position and B
It becomes a posture. Then, the developer accumulated at the bottom of the developing tank 1 is collected by the carrying-out means 51 by the rotation of the developing tank 1. During the rotation of the developing tank 1, the developer is attracted by the magnetic force of the developing roller 2 and therefore does not spill from the opening 10.

When the collection container 4 is attached to the discharge port 5, the detection switch 56 detects that the collection container 4 is attached, and the fourth controller 52 drives the developing roller 2, the stirring roller 3 and the discharging means 51, and the developing tank 1 The developer in the inside is accumulated in the holding portion 55 located below the developing tank 1 by the rotation of the developing roller 2 and the stirring roller 3, is conveyed to the discharge port 5 by the discharging means 51, and is collected in the collecting container 4. .

After a certain period of time, the developing roller 2, the stirring roller 3, and the carry-out means 51 are stopped, and the recovery container 4 is removed from the developing tank 1. Then, when the developer exchange switch 21 is turned on again, the rotary shaft 50 is driven, and the developing tank 1 is moved from the B-position to 18
It rotates 0 degrees and becomes A posture. Then, the toner replenishing tank 53 is removed from the developing tank 1, and a new developer is introduced through the communication port.

Therefore, in this embodiment, since the developer is automatically collected, the user can easily replace the developer without stains.

[Fifth Embodiment]

FIG. 13 is a sectional view of the developing device of the fifth embodiment during image formation, FIG. 14 is a sectional view of the same when a developer is replaced, and FIG. 15 is a control block diagram of the same.

The developer collecting device of this embodiment includes a conveying means 57 that is arranged under the developing tank 1 so as to be collected and conveys the developer to the collecting container 4, a shutter 7 that opens and closes the discharge port 5, and the developing roller. 2. A fifth control device 58 for controlling the driving of the agitating roller 3 and the conveying means 57 and the opening / closing of the shutter 7 is provided, and the fifth control device 58 controls the developing roller 2 and the agitating roller 3 during image formation. And the conveying means 57 are rotated in opposite directions to form an image forming function of closing the shutter 7 in a closed posture, and the developing roller 2, the stirring roller 3 and the conveying means 57 are rotated in the same direction when the developer is replaced. And a developer collecting function for opening the shutter 7 in the open position.

Since the structure of the developing tank 1 and the conveying means 57 are the same as those in the first embodiment, detailed description thereof will be omitted.

However, the transport screen of the transport means 57 is used as the developing roller 2
When the toner is driven to rotate in the same direction as the agitating roller 3, especially in a high-speed machine having a high image forming speed, if the agitating ability between the replenished toner and the developer is weak, sufficient triboelectrification cannot be obtained, and toner scattering This may cause fogging, which may result in stains around the device and deterioration of image quality.

Therefore, in the present embodiment, the transport screw as the transport means 57 is provided with a reverse rotation mechanism composed of a clutch and a gear so that the rotation direction can be switched.

Further, the fifth control device 58 is composed of a micro computer, and when the developer exchange switch 21 is turned on or when the developer exchange simulation mode is set, the fifth device 58 causes the developer recovery function to operate and the transfer means 57 to operate. The reverse rotation mechanism is operated so as to rotate in the same direction as the developing roller 2 and the stirring roller 3.

In the above structure, the fifth control device 58 is used during image formation.
The developing roller 2 and the agitating roller 3 are rotated in the counterclockwise direction, the conveying means 57 is rotated in the clockwise direction, and the shutter 7 is placed in the closed posture. When the developer is replaced, the developing roller 2, the agitating roller 3 and the conveying means 57 are rotated. Is rotated counterclockwise to open the shutter 7 to recover the developer and supply a new developer as in the first embodiment.

Therefore, also in this embodiment, the developer can be collected and put in automatically, and the user can easily carry out the work without stain.

Moreover, at the time of image formation, by making the rotating direction of the conveying means 57 different from that of the developing roller 2 and the stirring roller 3, the circulation efficiency of the developer is improved and all of the developer can be used sufficiently and uniformly. Since the developer has a long life and the replenished toner is efficiently mixed with the developer, sufficient chargeability can be maintained, and high image quality can be achieved by preventing toner scattering and fogging. Therefore, it can be used especially in the field of high-speed machines.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, as shown in FIG. 16, the carrying means 6 or the carrying-out means 51 uses a magnetic belt 61 wound between a pair of rollers 60, and a scraping plate 62 is provided at the discharge port 5 to attach the magnetic belt 61 to the magnetic belt 61. Alternatively, the developer conveyed and then scraped by the scraping plate 62 may be used. Further, as shown in FIG. 17, a rubber belt 63 may be used instead of the magnetic belt 61, and a carrier plate 64 may be provided on the outer peripheral surface thereof.

As a reverse mechanism of the transport means 57 in the fifth embodiment, a motor dedicated to the transport means 57 may be provided and the rotation of the motor may be switched.

<Effects of the Invention> As is apparent from the above description, according to claim 1 of the present invention, a conveying means arranged below the developing tank for conveying the developer to the collecting container, and the conveying means are exposed and shielded in the developing tank. A covering means is provided so that the developing roller, the stirring roller and the conveying means are driven at the time of exchanging the developer, and the covering means is operated so that the conveying means is exposed. Can be performed automatically and can be easily performed by the user without getting dirty.

Further, at the time of image formation, the bottom of the developing tank is closed by the covering means, so that the amount of the developer used can be reduced and the developer accumulated at the bottom of the developing tank can be reduced. Utilization efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a developer collecting device of a developing device showing a first embodiment, FIG. 2 is a sectional view of the same developing device, FIG. 3 is a control block diagram of the same, and FIG. 4 is a second embodiment. FIG. 5 is a side view of the developer collecting device of the developing device, FIG. 5 is a sectional view of the developing device, FIG. 6 is a control block diagram of the same, and FIG. 7 is a developer collecting device of the developing device showing the third embodiment. A side view, FIG. 8 is a sectional view of the developing device, FIG. 9 is a control block diagram of the same, FIG. 10 is a side view of a developer collecting device of the developing device showing a fourth embodiment, and FIG. Cross section of the device,
FIG. 12 is the same control block diagram, FIG. 13 is a sectional view of the developing device showing the fifth embodiment at the time of image formation, FIG. 14 is a sectional view of the same when replacing the developer, and FIG. 15 is a similar control block diagram. ,
FIG. 16 is a front view showing another embodiment of the conveying means, and FIG. 17 is a front view of another embodiment of the same. 1: developing tank, 2: developing roller, 3: stirring roller, 4: developer collecting container, 5: developer discharging port, 6: conveying means, 7: shutter, 8:
First control device, 30: coating means, 31: second control device, 40: third control device, 50: rotating shaft, 51: developer discharging means, 52: fourth control device, 57: conveying means, 58: Fifth control device.

Front Page Continuation (72) Inventor Seiko Mototsuka 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture (56) References JP-A-2-141779 (JP, A) JP-A-53-49439 ( JP, A) JP 55-153969 (JP, A) JP 64-18166 (JP, A) Actual opening HEI 1-177763 (JP, U) Actual opening 61-135350 (JP, U)

Claims (1)

(57) [Claims] 1. A developing tank, a developing roller and an agitating roller are rotatably mounted inside, a developer collecting container is attached to one end of the developing tank, and a developer discharge port is formed between the developing tank and the collecting container. And a conveying means arranged below the developing tank for conveying the developer to the collecting container, a covering means for exposing and shielding the conveying means in the developing tank, the developing roller, the stirring roller, the conveying means, and A control device for controlling the drive of the covering means is provided, and the controller drives the developing roller, the stirring roller and the conveying means at the time of replacing the developer, and operates the covering means so that the conveying means is exposed. A developer collecting device for a developing device, which is provided with a developer transport function for causing the developer to recover.